Sash operating mechanism



June I, 1943. 3, w UMM|NGS 2,320,413

SASH OPERATING MECHANISM Filed April 29, 1940 ATTORNEY.

Patented June 1, 1943 UNITED STATES PATENT OFFICE SASH OPERATING MECHANISM Gerald W. Cummings, Dallas, Tex.

Application April 29, 1940, Serial No. 332,156

1 Claim.

This invention relates to sash control mechanism for windows and it has particular reference to such mechanism wherein the cords or other means by which the sashes are raised and. lowered are under uniform tension.

The principal object of the invention is to minimize the space usually required for the operating mechanism for window sashes and to reduce the effort required to raise and lower counter-balanced sashes. The invention affords a counterbalancing means disposed at one side of the sash frame, yet maintaining on the sash cords an equal tension in order to eliminate friction between the sash edges and channels.

Another object of the invention is to provide a novel form of cord tensioning means in which the tension is kept constant and through the medium of which, the sashes may be raised and lowered by pull cords adjacent the frame of the window, thereby aifording a feature of advantage especially when Venetian blinds are used.

With the foregoing objects as paramount, the invention has further and lesser objects and salient features of construction to become manifest as the description proceeds, taken in connection with the accompanying drawing, wherein:

Figure l is an elevational view of a window showing the invention in operative position there- Figure 2 is a plan view of flexible lines, pulleys and tensioning means shown in Figure 1.

Figure 3 is a detail view in transverse section of the tensioning means for the flexible lines on line 3--3 on Figure 2.

Figure 4 is an elevational view in detail of the sash pull roller and cords, shown in Figure 2.

Figure 5 is a transverse section on line 5-5 on Figure 4.

Figure 6 is a modified form of the invention shown in the preceding figures, wherein a weight is substituted for the spring counterbalance, and

Figure 7 is a plan view of that portion of Figure 6 embraced by line 1-1.

For purposes of illustration, only the lower sash of a double hung window is illustrated. Obviously, the mechanism for operating the upper sash would be a duplication of that shown except for the threading of the flexible lines, such as cords or metal tape, over the pulleys.

Continuing with a more detailed description of the drawing, I designates a window frame which, it will be noted, does not require the usual weight boxes which constitute the side portions of the frame. Instead, the frame is comprised of relatively narrow timbers 2 with moulding 3 providing channels for the sashes 4 and 5.

Attached at a to the upper portion of the sash 5 is the end of a metal tape 6, the latter extending upward in the sash channel and across pulley I and over pulley B thereabove. The tape then extends across the top of the window in the sash groove to the double grooved pulley 9 to which the opposite end of the tape is secured. The opposite side of the sash 5 has one end of a companion tape I0 secured thereto at b and extends upward in the opposing sash channel, over the double grooved pulley I I, thence to the pulley 9 to which the opposite end'is fixed.

The double grooved pulley 9, just referred to is keyed to a stub shaft I2 and has integral therewith a spirally grooved pulley I3 (Figure 2). The purpose of this latter pulley will become apparent presently.

Adjacent the pulley combination 9I3, pulley I I is mounted freely on stub shaft I4 and carried by the same shaft is a spirally grooved pulley I5, similar to and cooperating with companion pulley 13 through the medium of a cord I6. The pulley i5 is provided with a circular cavity I'l containing a coiled sprin I9, one end of which is secured to the shaft I4 at c, the outer end being secured at d to the pulley I5. A washer 2B separates the two pulleys II and I5.

It is apparent from the foregoing that tension of spring I9 will tend to wind the cord IE on the pulley i5, causing it to rotate the companion pulley I3 as it unwinds therefrom. In thus rotating the pulley I3, the tape 6 and I0, connected to either side of sash 5, winds in separate grooves of the double grooved pulley 9 which, as stated, is a part of the spirally grooved pulley I3. Accordingly, the two lengths of tape 6 and HI are at all times under tension, made more or less constant by the fact that as the cord I6 winds upon the coniform pulley I5 from the large to the small diameter thereof, tension of spring I9 is moderated in proportion to the distance traveled by the sash.

It is to be observed that none of the pulleys extend above the head of the window frame to conserve space although the control pulleys 9 and I I do extend beyond the side of the frame. This is for the express purpose of affording an auxiliary means for raising and lowering the sashes. For this purpose, a double grooved pulley 2| is fixed to the shaft I2 (Figure 2), which extends through the wall adjacent to the window and spaced therefrom. A cord 22 is secured in one of the grooves of the pulley and depends along one side of the window. Another cord 23 is secured in the companion groove and depends parallel to the cord 22. A pull exerted on cord 22 .will wind tape 6 and It] on pulley 9, causing sash 5 to raise while a pull on the companion cord 23 will lower the sash.

In Figures 6 and 7 is shown a modified form of the invention, modified in the sense that a weight 24 counterbalances the sash instead of the spring as in the previously described embodiment. In this form, a length of metal tape 25 is secured at a to the sash 26 at one side, extends upward across pulley 27, over pulley 28, across the top of the window and is wound on the single grooved pulley 29, afiixed to shaft 30. A companion length of tape 3| is afiixed at b to the opposite side of the sash and extends upward and over pulley 32, mounted on shaft 33, and is likewise wound on pulley 29 under the tape 25, as shown. The weight 24 is suspended by a cord 34, the latter being wound upon a grooved pulley 35, mounted on the shaft 30. It will be seen therefore that the weight 24 will descend as the sash 26 is raised, maintaining tension on both tapes 25 and 3| as they both wind upon pulley 29. Sash operating cords 36 and 31 are provided on the pulley 38 to raise and lower the sash, respectively. It will be noted that the weight pulley 35 is of larger diameter than the companion pulleys. This is for the purpose of increasing the degree of leverage in order that smaller weights may be employed with the same result. The weight in the present case, due to the oversize pulley, is permitted to travel a greater distance than the sash as the latter is raised and lowered.

Manifestly, the construction as shown and described is capable of some modification and such modification as may be construed within the scope and meaning of the appended claim is also considered to be within the spirit and intent of the invention.

What is claimed is:

In a window sash control, a sash counterbalance comprising the combination of a pair of pulleys disposed one above the other adjacent the upper corner of a window frame, a double grooved pulley disposed at a point spaced greater than the width of said frame from the opposite corner -of said frame and whose shaft is parallel with those of said pair of pulleys, a coniform, spirally grooved member integral with said double grooved pulley, a second double grooved pulley intermediate said pair of pulleys and said first grooved pulley whose shaft is also parallel to the shafts of said first pulleys, a coniform, spirally grooved member mounted on the shaft of said second pulley but independent thereof, a, spring encased in said latter coniform member urging rotation thereof in one direction, a cord operatively connecting said spirally grooved members, a flexible line connected to one side of a sash, extending around said pair of pulleys and wound in one of the grooves of said first pulley, a companion line connected to the opposite side of said sash, extending over said second grooved pulley and Wound upon said first grooved pulley whereby the tension of the spring of said coniform member will be transmitted to said second grooved pulley through said cord to counterbalance said sash, an operating pulley mounted on the shaft of said first grooved pulley and operating cords wound upon said operating pulley.

'- GERALD W. CUMMINGS. 

